Conventionally, processing a black-and-white photographic product comprises a development step, a fixing step and a washing step. The processing of color photographic products comprises a color development step, a bleaching step, a fixing step and a washing step. These processing steps are generally implemented in processing tanks in which the photographic product is immersed.
With methods of processing in tanks, the processing solutions lose their active principles and become loaded with contaminating compounds coming from the photographic product itself or the adjacent processing solutions. The result is a reduction in efficacy of the photographic solutions, that requires the use of replenishing solutions. In particular, the developers that transform the latent image into a silver image by reducing the silver ions become loaded with halide ions coming from the photographic film. The halide ions, in a high concentration in the developing solution, greatly slow down the efficacy of the developer.
The conventional technique of processing in tanks makes it necessary to use large quantities of solution. In addition, the destruction or recycling of these large volumes of solution gives rise to many problems, in particular with respect to environmental protection. These problems are all the greater since the standards for discharging chemical solutions are becoming more and more severe.
In order to limit the problems related to the use of a large volume of solution, it appears advantageous to have a method of developing a photographic product by the surface application of a developing solution.
The technique of development by surface application of a layer of developing solution makes it possible to reduce considerably the volume of processing solution useful for the development, and consequently all the problems of recovery, recycling or destruction. However, the known methods which use this technique present drawbacks. They require for example additional processing steps that are often complex, such as for example the conditioning of the developing solution. In addition, these methods have not made it possible to obtain satisfactory sensitometric results.